The invention concerns a device for recirculating oil from the area of the end face of the barrel and the peripheral surface of the roll neck of rolling mill rolls, which roll neck is supported in the bearing of a bearing chock, wherein a sealing race, which is arranged between the bearing elements and the end face of the barrel, is mounted on the roll neck.
It is well known that in rolling mill rolls, which are supported in and carried by bearing chocks, these bearings can be furnished with sealing races mounted on the roll necks against the roll necks of the roll and the roll barrel and can be sealed with additional flexible elastic gaskets, which partly form labyrinths and are connected with the roll neck and the bearing housing. The sealing devices generally satisfy the sealing requirements of a rolling operation.
In the rolling of rolled strip, for which quality requirements are especially stringent, e.g., in the case of rolling in dry temper rolling stands, the barrels of the rolls must be kept completely free of dirt and oil, since even a few individual drops of oil that get on the peripheral surface of the rolls in the rolling area from the bearing through the end face of the roll barrels have an adverse effect on the surface quality of the roll barrel and often make it necessary to change the rolls completely.
Attempts have already been made to admit compressed air into the sealing labyrinths to produce a flow of oil under the sealing races towards the bearing and thus to counteract this escape of drops of oil. This measure also proved unsuitable for reliably preventing the escape of individual drops of oil with the frequent result that the quality defects caused by the escape of oil were not detected until the inspection line following the rolling of the strip, usually not until after several coils of strip had been rolled, which by then all had the same defects.
The objective of the invention is to improve the previously known oil recirculation systems by eliminating the risk of the escape of even small amounts of oil with a high degree of reliability and with low maintenance expense.
This objective is achieved by a device of the general type described above for recirculating oil, which is characterized by a conical ring body with a conical outer surface and a cylindrical inner surface that is seated on the outer surface of the sealing race and is sealed from said race, such that the inclination of the conical outer surface towards the end face of the barrel runs towards the roll axis, and by an additional, second conical ring body that is rigidly mounted in the bearing housing and has a conical inner surface, which is arranged some distance opposite the conical surface of the first conical ring body, such that the two conical surfaces form a hydraulic pump gap that conveys oil away from the end face of the roll barrel.
In this regard, as the invention provides, the end of the pump gap that faces the roll barrel can open in an annular admission chamber, which is formed by lateral surfaces of the first conical ring body, which run in the radial direction relative to the axis and inclined thereto, by the radial lateral surface of a flange-like annular shoulder of the second conical ring body, which (radial lateral surface) lies some distance opposite the lateral surfaces of the first conical ring body, and by an outer surface section of the sealing race. In this regard, the outlet end of the pump gap that faces away from the roll barrel can open into an annular oil collection chamber, which is formed by a radially running lateral surface of the second conical ring body, by a lateral surface of a flange-like annular shoulder that is rigidly mounted in the bearing housing and lies some distance opposite the aforesaid lateral surface of the second conical ring body, and by a sidewall section of the first conical ring body, such that radial conveying channels, which are located in the bearing housing, and an outlet channel, which is located downstream of the radial conveying channels, are assigned to the oil collection chamber.